Scientists Discover Dark Electrons: A Hidden Quantum State in Solid Matter

If you had a flashlight with you and directed it at a blank wall you would expect it to give a straight line projection however you will find the lit up wall forming rings where the flash light is pointing at. This occurs due to interference and constructive as the light wave forms combine or destructively when the waves structure is out of phase. This occurs when the two waves are in phase with each other thereby producing constructive interference which brought about a bright region. When they do not occur, destructive interference is experienced thus causing the light to fade. Mathematically if S and N waves are 1800 out of phase the interference actually nulls the signal completely.

Although, light is the most familiar interference, the concept of Interference is not restricted to it. Electrons can also interfere when they have juxtaposable different energy, this leads to the formation of the ‘‘dark electrons’’, electrons in ‘‘dark state’’ not visible by spectroscopic equipment.

Until recently, it was believed that such dark electrons can not be present in solids materials. The problem was that in the solid matter electrons are packed very closely together and thus it was thought to be virtually impossible to reach such ‘perfectly different energies’. Still, the research work conducted by a team from South Korea has revealed that these dark states do exist in condensed matter. This finding, published in Nature Physics can change how quantum physics is perceived.

“This hidden state could be the missing link that has been sought to explain other hard-to-explain quantum phenomena,” the researchers said. “Coalescing other yet unidentified dark states in nature and studying their dynamics is of paramount significance. ”

The team probed these dark states in palladium diselenide or PdSe2, which is a crystalline material. While observing electron behavior they saw that there were entire energy bands they should be able to see, but were missing. What they did was to guarantee that the dark states stemmed not from the light they employed, but from the electrons.

The researchers then extend their newly-found dark states to other systems and concluded that such dark electrons may exist in many material systems including PdSe2. As study co-author Keun Su Kim suggested this might help to explain why some materials can become superconductors in some conditions which are not expected. Quantum behavior which could have been hidden for a long time could have hidden our understanding of these phenomena but now that we have this knowledge we can solve these mysteries.

In science, darkness is normally associated with mystery. The great thing about such a show is that while solving one enigma unveils another, the more profound enigma in this case.